Allow TextButton derivatives to override drawing of certain parts.

ui/views/controls/button/text_button.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_CONTROLS_BUTTON_TEXT_BUTTON_H_
 #define UI_VIEWS_CONTROLS_BUTTON_TEXT_BUTTON_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 166 matching lines @@
   // states change.
   virtual void UpdateColor();
 
   // Updates text_size_ and max_text_size_ from the current text/font. This is
   // invoked when the font list or text changes.
   void UpdateTextSize();
 
   // Calculate the size of the text size without setting any of the members.
   void CalculateTextSize(gfx::Size* text_size, int max_width);
 
+  // Paint the button's text into the specified canvas. If |mode| is
+  // |PB_FOR_DRAG|, the function paints a drag image representation. Derived
+  // can override this function to change only the text rendering.
+  virtual void OnPaintText(gfx::Canvas* canvas, PaintButtonMode mode);
+
   void set_color_enabled(SkColor color) { color_enabled_ = color; }
   void set_color_disabled(SkColor color) { color_disabled_ = color; }
   void set_color_hover(SkColor color) { color_hover_ = color; }
 
   bool use_enabled_color_from_theme() const {
     return use_enabled_color_from_theme_;
   }
 
   bool use_disabled_color_from_theme() const {
     return use_disabled_color_from_theme_;
@@ skipping 124 matching lines @@
   void set_full_justification(bool full_justification);
 
   // Overridden from View:
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   virtual const char* GetClassName() const OVERRIDE;
 
   // Overridden from TextButtonBase:
   virtual void PaintButton(gfx::Canvas* canvas, PaintButtonMode mode) OVERRIDE;
 
  protected:
+  // Paint the button's icon into the specified canvas. If |mode| is
+  // |PB_FOR_DRAG|, the function paints a drag image representation. Derived
+  // can override this function to change only the icon rendering.
+  virtual void OnPaintIcon(gfx::Canvas* canvas, PaintButtonMode mode);
+
   gfx::ImageSkia icon() const { return icon_; }
 
   virtual const gfx::ImageSkia& GetImageToPaint() const;
 
   // Overridden from NativeThemeDelegate:
   virtual ui::NativeTheme::Part GetThemePart() const OVERRIDE;
 
   // Overridden from TextButtonBase:
   virtual void GetExtraParams(
       ui::NativeTheme::ExtraParams* params) const OVERRIDE;
@@ skipping 24 matching lines @@
   // True if the icon and the text are aligned along both the left and right
   // margins of the button.
   bool full_justification_;
 
   DISALLOW_COPY_AND_ASSIGN(TextButton);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_TEXT_BUTTON_H_